Alessandra Ambrosio stays fit by following a portion-controlled diet and doing rigorous workouts that include cardio exercise, running stairs and doing calisthenics with ankle weights.

“I put 5-pound ankle weights on each leg, get on all fours and kick each heel up toward the ceiling [to work my butt],” said Alessandra. “I do three sets of 20. Then I also do three sets of 20 fire hydrants, where you lift each bent leg up and out to the side.”